The council gave Germany the top score as it credited Europe's largest economy for its mandatory codes on residential and commercial buildings as it works to meet a goal of reducing energy consumption by 20% by 2020 from 2008 levels.

"We are pleased to win a second title in a week's time," Philipp Ackermann, the deputy chief of mission at the German embassy in Washington, told a conference call, alluding to his country's World Cup victory.

Echoing the views of the report's authors, Ackermann pointed out that Germany has achieved economic growth while improving efficiency and reducing harmful environmental effects of the energy trade.

"We all agree , I think - the cheapest energy is the energy you don't have to produce in the first place," Ackermann said.